Thermostat



Patented July 8, 11924.

, I 1,500,566 PATENT l OFFICE...

LEE P. HYNES, OF ALBANY, NEW YORK, ASSIGNOR TO CONSOLIDATED CAR-HEATINGCOMPANY, OF ALBANY, NEW YORK, A CORPORATION OF WEST VIRGINIA.

Y THERMOSTAT.

Application led April 18, 1922. Serial No. 555,173.

To all 'whom it may concern:

Be. it known that I, LEE P. HYNES, a

citizen of the United States, residin at f Albany, in the county ofAlbany and tate of New York, have invented certain new and usefulImprovements in Thermostats, the following being al full, clear, andexact i disclosure of the one vform of my invention which I at presentdeem preferable.

lFor a detail description of the' present form of my invention,reference may be had to the followin speciication and to theaccompanying drawings forming a part thereof, wherein- Fig. 1 is alongitudinal section;

Fig. 2 a front view with cover removed;

' Fig. 3 is a rear view, with the base removed, and

Fig. 4 is a transverse section on lines 20 4 4 of Fig. 1. My inventionrelates to a thermostat of the mercury type designed to open and Jclosean electric circuit at predetermined temperatures. Heretofore it hasbeen roposed to connect the thermometer bulb 1n a thermostat of thistype with a cover-plate of special heat-responsive metal, through whichthe temperature-changes in the outer atmosphere are communicated to thebulb. In this device, the large surface of heatresponsive metal,together with the-other metal parts associated therewith tend to makethe action of the device sluggish, its response to temperature changesbeing so gradual as to impair the electric contacts, particularly on theopening of the circuit.

Moreover, such instruments areA ordinarily mounted on the wall of a caror apartment wherein heat is inevitably stored, and soon come to partakeof such stored heat and acquire a temperature that is not quicklychanged by changes in the atmospheric temperature.

My invention resides in the use of a comparatively small heat-responsive'element which is effectively heat-insulated from the cover or casingbut applied directly to the thermometer-bulb. This element is exposed tothe atmosphere on the outside of the cover or casing but isheatinsulated therefrom and passes ythrough narrow slots into the insideof the casing where it is wrapped around the bulb of the thermometer. Bythis means I secure a movement of the mercury column that isheat-responsive quick and positive such as is needed for opening anelectric circuit at the contacts D. I am also enabled, by thisexpedient, to use a cover or casing of heavy steel plate that willadequately protect the delicate glass thermometer inside of it.

In the drawing, A represents a base of moulded material and B a metalcasing or cover of steel suitably secured to the base.

On the inside of cover B is a mercury `thermometer of glass having metalcontacts D, D, set therein and exposed to the mercury within the glasstube, but without breaking the vacuum therein. From each of the contactsD, a wire leads to one of the tubular terminals E, E set in the base Eand provided with binding screws in each end. Thermometer'C is mountedat one end in a cushioning bushing and at its lower, or bulb-end, issurrounded by a strip G of thin copper or other composition that issensitive to changes of temperature. The bulb is lightly clamped withinthis strip G by a screw g, as is shown in Fig. 4 and the strip itselfextends thence through a narrow slot in the casing B, and, after passingacross the outer face of the casing passes back into it through asimilar slot on the opposite side and is there bent over to secure it inplace. A layer of heat-insulating material F separates and insulates thesensitive strip G from the metallic casing or cover B, on all sides,whereby its response to heatvariations are independent thereof. Thatserves toeliminate the slow and uncertain effects of heat-variations inthe steel cover B from the mercury of the thermometer. The mercuryresponds directly to the heat effects in sensitive strip 21 Withoutdisturbance by the effects in the casing- B.

This will be realized by considering that the exposed portion of strip Gis comparatively small and has but a slight capacity for heat storagealthough of good heatconducting capacity. Therefore it canreceive or-lose heatto its 'full capacity long before there can be any materialflow of heat in either direction through the insulating layer F from orto the mass of heat in the casing itself and the wall on which it ismounted.

What I claim as new and desire to secure by Letters Patent is: y

1. A thermostatie control-device comprising a base, a cover cooperatingwith said base to provide an enclosure, a thermostat and an element oftemperature-sensitive material applied to said thermostat within saidinclosure, a portion of said temperaturesensitive material being exposedv,to the atmosphere outside of the inclosure and actf port.

ing on the thermostat independently of the enclosure and an electriccontact controlled the thermostat.

2. A `thermostatic, control-device comprising a base, a covercooperating with said base to provide an enclosure, a thermostat, anelectric contact controlled by the thermostat and an element oftemperature-sensitive material applied to said thermostat within saidenclosure, said material having a portion thereof passed through sai-dcover for external exposure to the atmosphere whereby said element willact on the thermostat independently of the enclosure.

' 3. A thermostatic control-device compris- -ing means providing anenclosure, a thermotat within said enclosure, an electric contactcontrolled thereby a temperature-sensitive element applied to thethermostatic device within the enclosure, means for supporting saidelement with a portion thereof exposed to the atmosphere outside of saidenclosure and. means for insulating said element from temperaturechanges of its supcontrolled by said thermometer and a temupon saidenclosure, an electric contact controlled by said thermometer, atemperaturesensitive element constructed independently of theenclosure-forming means, vsaid element engaging the bulb end of thethermometer and having a portion exposed to the outside atmosphere andmeans for insulating said temperature-sensitive element from temperaturechanges of the enclosureforming means.

7. A thermostatic control-device comprising a base, a cover cooperatingwith said base to provide an enclosure, a thermometer within saidenclosure, an electric contact controlled by saidvthermometer and atemperature sensitive element secured to and heat insulated from saidcover, said element engaging the bulb end of the thermometer and havinga portion exposed to thev outside atmosphere.

8. A thermostatic control device comprising a base, form an enclosure, athermometer within said enclosure, an electric contact controlled bysaid thermometer, a lbulb-engaging clip formed of temperature sensitivematerial having a portion thereot` extended through said cover, wherebysaid portion is exposed to the -externalatmosphere and the clip issupported and means for insulating said clip from temperature changes ofthe cover.

Signed at Albany, county of Albany and State of New York, this 13th dayof April,

LEE P. HYNES.

a cover cooperating therewith to

